Asthma is a high prevalence, costly disease. Peak expiratory flow monitoring (PFM) is an inexpensive objective measure of airway obstruction, widely used for self-monitoring of moderate to severe asthma. Along with symptoms, PFM measures drive the asthma "action plan". BREATH is a pocket-sized, easy to use electronic information appliance designed for use by children with asthma. It contains a digital asthma diary and dynamic action plan engine, using embedded statistical process control (SPC) logic. SPC algorithms will analyze the "noise" variations inherent in PFM values, creating more sensitive and specific action points. A clinic- based BREATH server uploads, stores, and analyzes data from a population of BREATH client users. Hypothesis: 1) BREATH will be accepted by children with asthma, improving record-keeping ad treatment adherence; 2) knowledge derived from SPC-analyzed PFM data will prove superior to raw PFM data in driving asthma action plans, 3) asthmatic children will experience outcome and treatment satisfaction improvements as a result. Phase I research focuses on laboratory and clinical acceptance testing with asthmatic children and expert clinicians. Phase II would refine BREATH, incorporating a peak flow meter based on new flow sensor technology, and conduct a multi-center randomized controlled clinical trial focused on outcomes and cost effectiveness. PROPOSED COMMERCIAL APPLICATIONS: The market for self-management aids in the health arena is growing rapidly. U.S. health policy, as reflected in Healthy People 2000, emphasizes a shift toward self-care of chronic diseases like asthma. We are targeting BREATH toward a marketplace driven by concerns for both quality care and cost with projections for a final product selling for under $250. We believe that the commercial potential for this product is large.